(19)

(11)

EP 0 516 753 A1

(12)

(43) Date of publication: 09.12.1992 Bulletin 1992/50 (21) Application number: 91905999.0 (22) Date of filing: 21.02.1991

(51) International Patent Classification (IPC):  C12Q 1/ 68( . ) G01N 27/ 447( . ) C12Q 1/ 70( . ) G01N 21/ 78( . ) G01N 33/ 58( . ) (86) International application number: PCT/US1991/001176 (87) International publication number: WO 1991/013174 (05.09.1991 Gazette 1991/21)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 26.02.1990 US 19900484573 (71) Applicant: THE UNITED STATES OF AMERICA as represented by the Secretary UNITED STATES DEPARTMENT OF COMMERCE Washington, DC 20002 (US)	(72) Inventors: HUGHES, Stephen, H. Smithsburg, MD 21783 (US) BRUMBAUGH, John, A. Lincoln, NB 68506 (US) KUMAR, Ramesh Pennington, NJ 08534 (US) (74) Representative: Perry, Robert Edward  GILL JENNINGS & EVERY Broadgate House 7 Eldon Street London EC2M 7LH London EC2M 7LH (GB)